Re: http with S ... again.
As I recall, the basic certificate itself from Let's Encrypt is free. Others with more sophisticated security have a cost. Nevertheless, the hosting server has to be configured to allow the security certificate for it to work. I'm not sure about Xara's domain service.
Re: http with S ... again.
Xara's domain service is not SSL compliant.
Acorn
Re: http with S ... again.
My clients use godaddy. I will host my future website with a Canadian company to support Canadian tech and also it helps with local SEO. So find a local hosting company and make sure they have been in business and have a good record.